Wave-signaling system



E. H. ARMSTRONG July 14, 1925. 1 1,545,724

WAVE SIGNALING SYSTEM Filed Juxie a, 1922 f4 Q INVENTOR BY 7 gawk, M /Md ATTORNEY? it Patented July 14, 1925.

UNITED STATES P ATENT OFFICE.

-EDWIN H. ARMSTRONG, OF YONKERS,- NEW YORK, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO WESTINGHOUSE ELECTRIC 6'0 MANUFACTURINGCOMPANY, A CORPORA- TION OI PENNSYLVANIA,

WAVE-SIGNALING SYSTEM.

Application filed June 8,

Tooll whom it may concern:

Be it known that I, EDWIN H. ARMSTRONG, residing'at 1032 WVarburton Avenue, Yonkers, in the county of Westchester, State of New York. have invented certain new and useful Improvements in Wave-Signaling Systems; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to an electric regenerative system for amplifying varying electric currents, particularly radio or other high frequency signaling currents, wherein the varying potential of the current to be amplified is impressed on the system and. the relation between the amount of regeneration and the degree of damping of the system is periodically varied to produce transient free oscillationsproportional to the amplitude of the impressed potential and wher n the resulting tree oscillations and the system are continuously maintained in this transient ordinarily unstable state to obtain superregenerative amplification or action as described in my Patent 1,424,065 granted July 2:), 1922, on a co-pending application, Serial No. 480,563 filed June 27, 1921.

The invention has for its object the provision of a method of and apparatus for obtaining increased amplification with superregenerative systems, particularly of the type in whichthe amount of regeneration, that is, the regenerative energy supplied to the system (the so-called negative resistance) is varied with respect to the degree of damping, that is, the rate of dissipation of the energy of the system.

It has been discovered in the course of operation of super-regenerative systems in which the amount of regeneration is varied with respect to the degree of damping of the system, particularly when employed for the amplification and reception of radio telephone signals, that it is necessary to add positive resistance to; the tuning circuits of the system in order to preserve the quality of the received speech. The addition of positive resistance" to the circuit, however, is accompanied by a loss in intensity. To the end of overcoming this difliculty and for the purpose of introducing the necessary re sistance or damping in the tuned circuit in 1922. Serial No. 566,683.

such manner that a. loss in signal strength does not occur, an arrangement is provided grid of the vacuum valve of the regenerative system it acts as a step-up transformer; By coupling such a winding to the proper degree with the tuned circuit, the necessary amount of resistance is introduced in that circuit by the withdrawal of energy from it into the secondary winding. Instead, however, of the energy being wasted in a dead resistance, the energy withdrawn from the circuit is used to create an increased difi'erence of potential across the secondary ofthe transformer which is then applied to the grid of the vacuum tube '01 valve.

The particular form of circuit arrangement illustrated in the drawing is the pieferred embodiment of the invention. It possesses marked advantages in that it suc cessfully introduces the necessary damping in the tuned circuit of the system in such manner that a loss in signal strength does not occur. I

Referring now to. the drawing which illustrates the general arrangement of the system; the source 1 of the incoming signal or the varying current to be amplified is associated with the circuit 2, 3 which is tuned to the frequency of the incoming signal or current to be amplified; A high resistance coil 4 is coupled to the tuned circuit and is connected to the grid 5 of the vacuum valve 6. The feed-back coupling 7 in the plate circuitof the valve 6 is ,asso' ciated with the resistance coil 4 and the tuned circuit 2, 3, and serves to control the amount of regeneration of the system. The second vacuum valve 8 connected in the plate circuit of the valve 6 is employed tosupply the auxiliary 'frequency to the regenerativc system for the purpose of periodically varying the relation between the amount of regeneration and the damping of the system, in this case serving to vary the amount of regeneration with I spect to the damping of the system. The oscillating system' furnishing the auxiliary frequency inserve to indicate the received signals.

, may

' cluding the valve 8 is connected to a source of alternating current 9 or other source of electrical oscillations and the plate circuit of the valve 8 includes a second tuned circuit 10, 11 adjusted to the frequency of the auxiliary frequency current. The telephones 12 and bypass condenser '13 are also included in the plate circuit of the valve 6 are;

course, other equivalent indicating devices be employed instead of the telephone receivers 12.

The operation of the system is simple and follows generally the mode of operation of superregenerative systems as described in the aforementioned patent. It will be understood, however, thatthe function of the coil& consisting of many turns of fine resistance wire is to withdraw energy from the tuned circuit 2, 3 and simultaneously serve as the secondary of a step-up transformer whereby an increase of potential is created across the coil which is then applied'to the rid 5 of the vacuum valve 6. In this way tie necessary damping is intro duced into the tuned circuit 2, 3 but in such manner that a loss in signal strength does not occur when the system is amplifying and receiving signals. s

In the normal operation of the system, the grid 5 does not become positive. Current, therefore, does not flow between the grid-and the filament. The grid, however, does change it potential. Moreover, the grid possesses-a certain capacity. In order to change its potential, therefore, a charge must flow to or from the grid. There must, therefore, be a current in the connection leading to the grid. This connection includes the coil 4. This coil is made of sufliciently high resistance so that, in spite of It is to be understood that the present invention is adapted to receive radio Sig-- nals, including radio telephone signals,- when associated with .an antenna, loop or other energy collecting device and to receive wired wireless signals (so-called wire carrier current transmission when associated with the conductors 0 such signals. It should also beunderstood that-modifications-may be made in the specific circuit connections above described without departing from the spirit and scope of the invention.

I claim: i

1. The method of obtaining increased amplification of signals with super-regnera: tive systems provided with a tuned circuit and having a certain degree of damping, wherein the relation between the amount of regeneration and the degree of damping is periodically varied, which comprises inductively increasing the energy abstracted from said tuned circuit, and effecting by said additional abstracted energy a corresponding increase of response of the system to signals, whereby the'additional abstraction of energy from said tuned circuit is without corresponding loss in signalling strength.

2. An electric regenerative system adapted to produce super-regenerative action comprising a feed-back clrcuit including a vacuum valve having grid, filament and plate elements; connected to their respective circuits, a circuit connected to the filament of said valve which includes an inductance a second circuit connected to the grid 'of' said valve which includes a coil having a high resistance said inductance adapted to serve as the primary and the coil of high resistance as the secondary of a transformer supplying an increased otential to the grid while efi'ectively lIltI01ClI1g resistance or damping in said first or primary circuit whereby the necessary. damping of the system is obtained substantially without loss in signal strength.

In testimony whereof I afiix my signature.

EDWIN H. ARMSTRONG. 

